The role of gut mucous gel in bacterial translocation during total parenteral nutrition (TPN) was studied in rats. Celloidin stabilization of dried cryostat sections of small intestine with the luminal contenets was used to preserve the intraluminal mucous gel layr for stainig by periodic acid-Schiff reaction. First, the postnatal development of mucous gel layr was investigated. Morphological differences in the mucous gel between the villi of the small intestine in rats of several postnatal ages were observed, most notably after the age of two weeks. It is suggested that the adhesive mucous gel layr, covering the intestinal epithelium in the small intestine, undergoes rapid development after weanig. Secondly, the distribution of fluorescein isothiocyanate dextran (FD) and mucous gel layr across the lumen of small intestine was observed as an investigation into the role of mucous gel on permeability during TPN.The plasma FD level after 1 hour of this marker injection showed a significan
… Moret increase in TPN group compared with the rat food group. The mucous gel filled the spaces between villi and FD centered in the lumen in the rat food group, whereas the mucous gel decreased and FD filled the spaces between villi in the TPN group. These data suggested that TPN decreases permeability of small intestine in rats. Finnaly, in vivo effects of N-acetyl cysteine (NAC) as a mucolytic agent and colchicine (Col) as a suppressant of the mucous production on the intestinal transmission of FD.Plasma FD level in NAC group was higher than that in control group, that in Col+NAC group was higher than that in Col group and that in NAC group. The spaces between villi were filled with mucous gel in the control and Col groups, whereas those were not entirely filled with mucous gel in NAC and Col+NAC groups. FD and mucous gel showed complementary distribution in all rats. The villous interstitial edema was recognized in NAC group and villi were disrupted in Col+NAC group. These results suggest that intestinal permeability is possibly affected not only by the mucous gel covering the intestinal epithelium but also by mucous release from goblet cells of the small intesine.[結果]I.生後3日および1週ではvilli間隙が粘液で満たされるには至らないが2週目以降空腸、回腸ともにvilli間隙に粘液の存在が認められ、4週以降はこの粘液でvilli間隙が満たされた。II.TPN群ではvilliの萎縮が認められ粘液はvilli間隙を埋めつくす分布形態を取らず、FDがvilli間隙を満たす分布が認められた。血漿FD濃度はTPN群がCHOW群に比べて有意の高値を示した。III.血漿FD濃度はNAC群、Col+NAC群はそれぞれ対照群、Col群より高値を示し、またCol+NAC群はNAC群より高値を示し。即ち粘液産生抑制剤の腹腔内単独投与のみではFDの腸管透過性の亢進はみられず、一方粘液溶解剤の小腸管腔内投与により、FDの腸管透過性の亢進が認められ、両者の併用で更なる亢進がみられた。また対照群とCol群ではvilli間隙は粘液にて満たされておりFDには満たされていなかった。一方、NAC群とCol+NAC群ではかなりの部分がFDで満たされていた。対照群とCol群のvilliは正常であったが、NAC群ではvilliの浮腫が認められ、Col+NAC群ではvilliの損傷がみられた。以上、PMGの分布形態の変化が腸管透過性に影響を及ぼしTPN時のBTの一因になることが示唆された。 Less